The present invention relates to mobile repeaters, and more particularly to a system and method to dynamically manage the radiation pattern of the donor antenna of a mobile repeater system.
When an antenna system with configurable beam patterns is used as the donor antenna of a mobile repeater system a problem arises in that the antenna configuration must be adapted to the environment the repeater is operating in. If the antenna beam pattern can be continuously adapted to track the incoming signal as well as scan for new donor signals simultaneously, the problem is simple.
For example, assume the repeater donor antenna is an antenna array capable of simultaneously forming two beam patterns (similar to what is used in Multi-User MIMO systems). In this case, one beam pattern can be used to point to the donor base station and can be constantly adjusted to track the donor base station. The second beam pattern can then be used to scan for a more optimum donor base station and if one is found, the antenna configuration can be changed to point to the new donor base station. However, such an antenna system is complex and typically expensive to implement. Typically, a repeater donor antenna will have a single configuration only.
Assuming that only a single configuration is available, the problem is how to select the best configuration to be used and how to maintain an adequate input signal while the repeater moves.